But the massive showing just four weeks after Mr Macron’s surprise triumph in the presidential election was marred by record low turnout of below 50 per cent, the lowest in modern French history.

Rivals warned it suggested French democracy was “ill”.

Defying expectations that his new political party would struggle to wrest control of parliament from the traditional Right and Left, early exit polls suggested Mr Macron’s La République En Marche (REM) party, along with its centrist Modem allies, was on course to win around 33 per cent of the vote.

While many variables remain ahead of next Sunday’s second round, pollsters predicted the score could see REM, only created 14 months ago, and its ally take 415-445 of the 577 seats in the National Assembly — well over the 289 required for a majority.

“France is back”, said Mr Macron’s prime minister, Edouard Philippe. "For the third time running, millions of you have confirmed your attachment to the president's new project of renewal."

The nearest rival, the conservative Republicans, were trailing on around 20 per cent, another bitter blow for the mainstream Right, who only a few months ago had expected to win both the presidency and a parliamentary majority.

They stand to lose more than half their current seats to end up with 80 to 100, according to the exit polls.

François Baroin, their leader, called on Right-wingers to turn out en masse next Sunday, saying: “Our country expects balanced powers, not concentrated in a single party.”

Perhaps the biggest upset of the night was the poor showing of the far-Right Front National, which only won around 13 per cent of the vote compared to 23 per cent in the first round of presidential elections.

The drop could hand it as few as one-to-four seats, well short of the 15 it requires for a parliamentary group.

Leader Marine Le Pen said that despite the “catastrophic” abstention levels, her party could still win the day in “several constituencies”.

She came top in the northern Hénin-Beaumont district with 46 per of the vote, and will face a duel with a Macron candidate in round two in her third attempt to win a seat.

Meanwhile, the far-Left La France Insoumise party was seen as clinching around 12 per cent of the vote, and could win 10 to 20 seats. Its leader Jean-Luc Mélenchon was in pole position in his Marseille constituency.

The biggest losers of all were the Socialist Party, which only mustered around seven per cent of the vote – a catastrophic collapse five years after winning a parliamentary majority under the previous administration of historically unpopular ex-president François Hollande.

That could see them plummet, with Green and radical allies, to 30-40 seats. Jean-Christophe Cambadelis, the party’s secretary general, called it an “unprecedented setback for the Left and notably for the Socialist Party”.

Adding to the humiliation, he was eliminated from the runoff in Paris, as was the party's defeated presidential candidate, Benoît Hamon.

Mr Cambadelis said: “It is neither healthy nor desirable for a president who gathered only 24 percent of the vote in the first round of the presidentials and who was elected in the second round only by the rejection of the extreme Right should benefit from a monopoly of national representation.”

The result looks set to confirm the dramatic shake-up French politics that began with Mr Macron’s election on May 7, further punishing the traditional Left and Right and leaving no single strong opposition force.

His party's candidates include many newcomers to politics, including a retired bullfighter, a fighter pilot and a mathematical genius. Half are women.

To win in the first round, candidates need an absolute majority and support from at least a quarter of the district’s registered voters.

Otherwise, all contenders who get at least 12.5 percent of the support of registered voters advance to the second round.

Six ministers who had run for MP were on course to reach the runoff, including Richard Ferrand, the minister for social cohesion who is under preliminary investigation over a real estate controversy. They have been told they will have to leave the cabinet if they lose their parliamentary election.